The present invention relates to a field effect mode liquid crystal display (hereinafter called LCD) element incorprating a new electrode configuration, which effectively prevents the LCD elements from incorrectly displaying due to effect of a phenomenon called the "edge domain" phenomenon This phenomenon is generated in the dot pattern edge portion of the field effect LCD display elements used for a dot matrix display.
Conventionally, such a field effect mode LCD display element used for the dot matrix display contains electrodes having such a typical configuration shown in FIG. 1. FIG. 1-(a) shows a typical structure of such an electrode and FIG. 1-(b) a sectional view, respectively. Reference 1 is the lower glass substrate. Reference 2 is the upper glass substrate. Reference 3 is the common electrode formed on said lower glass substrate. Reference 4 is the segment electrode formed on said upper glass substrate and 5 indicates an LCD material. A dot display pattern is formed at the position where said common electrode 3 and segment electrode 4 cross each other, and is shown by means of hatching in FIG. 1(a). FIG. 2 shows the state of the arrayed LCD molecules when no field effect is applied (see FIG. 2-(a)) and when said field effect being applied (see FIG. 2-(b)), respectively. As shown in FIG. 2, LCD molecules are arrayed in a specific direction when no field effect is applied. Conversely, when the field effect is applied, LCD molecules that are present in the field-effect-applied position rotate to alter an optical characteristic of the display. Now, if only all the LCD molecules rise in a specific direction, a desired pattern comprising the correctly formed dots can be displayed. However, such an ideal pattern comprising the correctly formed dots is rarely displayed, and actually, a rectangular pattern is displayed without containing the display effect at the edge portion.
The cause of this symptom is described below. FIG. 3-(a) shows the relationship between the electrode position and the direction of the LCD molecules oriented to the glass substrate. When the segment electrode 4 formed on the upper glass substrate crosses the common electrode 3 formed on the lower glass substrate in a right angle, assuming that the orientation vector (a) against the upper glass substrate and the other orientation vector (b) against the lower glass substrate are respectively denoted by .theta.1=45.degree. and .theta.2=45.degree., the normal visual angle area can be provided in the direction of "6 o'clock". When this condition exists, the state of the LCD molecule array without the field effect indicates an orientation characteristics to the left, as shown in FIG. 3-(c). When using such a field effect mode LCD display element that contains the electrode configuration and means for processing orientation described above, it will display such a rectangular pattern 6 whose display content is partly absent from the edge portion 6a, as shown in FIG. 3-(c). However, when observing the display-lacking portion 6a in said edge from the upright 12 o'clock position, said portion 6a is visibly illuminated, causing a spotted pattern to be displayed. It is probable that such a phenomenon will take place only because, when electric signals are sent to both the common electrode 3 and segment electrode 4, the direction of the electric force line in said edge portion 6a may be disturbed, thus adversely affecting the direction of the rising LCD molecules, eventually causing them to be inversely oriented. In other words, LCD molecules are split into two parts; one is the portion 6b in which the LCD molecules normally turn, and the other is the portion 6a in which LCD molecules abnormally turn.